netroot handlers: Add argument checking

This is probably not necessary, but paranoia dictates that the actual
netroot handlers should check if all three required arguments (netif,
root, NEWROOT) are there and useable.

modules.d/95iscsi/iscsiroot

@@ -17,6 +17,16 @@ for conf in conf/conf.d/*; do
 	[ -f ${conf} ] && . ${conf}
 done
 
+# Huh? Empty $1?
+[ -z "$1" ] && exit 1
+
+# Huh? Empty $2?
+[ -z "$2" ] && exit 1
+
+# Huh? Empty $3? This isn't really necessary, since NEWROOT isn't 
+# used here. But let's be consistent
+[ -z "$3" ] && exit 1
+
 # root is in the form root=iscsi:[<servername>]:[<protocol>]:[<port>]:[<LUN>]:<targetname>
 netif="$1"
 root="$2"

modules.d/95nbd/nbdroot

@@ -12,6 +12,15 @@ if getarg rdnetdebug; then
     set -x
 fi
 
+# Huh? Empty $1?
+[ -z "$1" ] && exit 1
+
+# Huh? Empty $2?
+[ -z "$2" ] && exit 1
+
+# Huh? Empty $3?
+[ -z "$3" ] && exit 1
+
 # root is in the form root=nbd:server:port:fstype:fsopts:nbdopts
 netif="$1"
 root="$2"

modules.d/95nfs/nfsroot

@@ -12,6 +12,15 @@ getarg rdnetdebug && {
     set -x
 }
 
+# Huh? Empty $1?
+[ -z "$1" ] && exit 1
+
+# Huh? Empty $2?
+[ -z "$2" ] && exit 1
+
+# Huh? Empty $3?
+[ -z "$3" ] && exit 1
+
 # root is in the form root=nfs[4]:server:path:[options]
 netif="$1"
 root="$2"